/Engine/Source/Runtime/Experimental/Chaos/Public/PhysicsProxy/ClusterUnionPhysicsProxy.h
These functions take care of marshaling data back and forth between the game thread and the physics thread.
void PushToPhysicsState ( const [FDirtyPropertiesManager](API\Runtime\Chaos\Chaos\FDirtyPropertiesManager) & Manager, int32 DataIdx, const [FDirtyProxy](API\Runtime\Chaos\Chaos\FDirtyProxy) & Dirty )